Mom is a bit mad at me. How do I get her to at least try to understand?!?

Mom took me to a doctor today, mainly so that I can be put on birth control. She isn't so happy about my decision, because she thinks I'll have . The reason why she thinks I'll have is because, I kinda got caught making out with a guy friend a few days ago. I was at his house after school, and his mom wasn't home so we kinda went to his room and started making out on his bed. His mom got home early, and we got caught. I got in mega trouble for that, and our moms decided we can only see each other under "adult supervision". I understand that we are too young to have (he is 15 and I'll be 14 in a month), so I'm not like planing on that. The birth control is just in case. I tried to tell my mom that, but that didn't make things any better. She isn't talking to me unless it's necessary, and she is giving me her tough love routine. How can I get my mom to understand that I'm not planing on having sex any time soon?